Watts 740-1-40 Boiler Pressure Relief Valve

The Watts 740-1-40 Boiler Pressure Relief Valve provides reliable overpressure protection for hot water heating boilers. This Type Lever valve features a 1-inch inlet and a 1-1/4-inch outlet with female threaded ends for secure installation.

Built with an iron body and a stainless steel spring, the valve uses a metal seat paired with a non-metallic disc for dependable sealing. The set pressure range is 40 PSI, and it carries a temperature rating of 250°F with a nominal pressure rating of 30 to 75 PSI, ensuring safe operation across typical heating systems.

Designed to meet industry standards, it is ASME-compliant and follows NB, HV, MIL-V-18634B standards (Type I, Class 3A, Style B). The Watts 740-1-40 handles 925,000 to 2,649,000 BTU/hour, making it suitable for a range of hot water boilers. Overall dimensions are 3-1/2 inches wide by 7-1/4 inches tall.

• 1 in. inlet and 1-1/4 in. outlet with female threaded connections
• Iron body with stainless steel spring
• Non-metallic disc to metal seat
• Seat located above drain
• Test lever included
• Expanded outlet for improved flow
• Set pressure 40 PSI; 30–75 PSI range
• Temperature rating 250°F
• Capacity: 925,000–2,649,000 BTU/hour